wild yam is in

barbasco

barbasco—a term used for several plants that contain toxic chemical compounds used by indigenous populations to poison and catch fish (poisons that kill fish are called “piscicides”).

From the 1950’s until the 1970s there was a vigorous trade in one such fish-killing plant, the inedible, wild Mexican yam, Dioscorea mexicana.   The Mexican yam grows as an annual vine with an above-ground dome-shaped stem (called a “caudex”). The international traffic in Mexican yam was called the Barbasco Trade.  

The chemical diosgenin was extracted from the Mexican yam root.  It was used as a precursor for the synthesis of steroidal hormones such as progesterone, the basis of the first  generation birth pills.  

The Barbasco Trade ended when root began to be depleted in the wild and methods were developed to produce steroids from soy beans.  

Word origin:  The word “barbasco” is from Latin adjective barbascus, bearded. The Mexican yam is not particularly hairy, so technically the term used for Dioscorea mexicana is a misnomer.